Free, no sign-up — the PDF opens directly.

This is Systec's own manual for the DE-23, 219 pages long. It is the full document, exactly as supplied: free to download, with no sign-up.
Richmond Scientific buy, refurbish, test and resell this kind of equipment, so if you are working out whether a second-hand unit will do the job, the figures in the details panel are the ones to check it against.
Refurbished, tested and ready to ship from our Chorley warehouse.